Arcadius polesciiko



(No Model.)

A. POLESOHKO. ELECTRICAL TRANSFORMER.

464,677- Patented Dec. 8, 1891.

/V l A] l N i T R A A S l -13 ff W/T/VESSES: IIVVEA/TOH M mmm QMATTORNEYS UNITED STATES PATENT @EEICE.

ARCADIUS POLESCIIKO, OF ST. PETERSBURG, RUSSIA.

ELECTRlCAL TRANSFORMER.

SPECIFICATION forming part of Letters Patent No. 464,677, dated December8, 1891.

Application filed April 17, 1891. Serial No. 889,385. (No model.)

To aZZ whom it may concern.-

Be it known that I, ARCADIUS PoLEsoHKo, a subject of the Emperor ofRussia, and a resident of. St. Petersburg, Russia, have invented certainnew and usefulImprovements in Electrical Transformers, of which thefollowing is a specification.

All existing transformers may be classed in two groups. In the one (theRuhmkorff coil and the Gau'lard & Gibbs transformer) the iron core is inthe form of a cylinder. In the other the iron core is in the form of aclosed geometrical figure, annular (in the Zipernowski, Deri, and Blaty)or otherwise, (in the \Vestinghouse, Ferranti, &c.)' In transforn1- ersof the firstgroup the lines of force generated in the iron core by theaction of the primary helix are given off as a bundle from the northpole and proceed to the south pole across the outer space,wh ere theyform closed curves of all possible radii. The secondary coil in thiscase is in the intermediate space between the iron core and the exteriorsystem of line of force. In transformers of the second group all thelines of force generated in the iron core by the action of the primarycoil remain entirely in the core itself without appearing at theexterior. These lines of force remaining in the iron core can only passin the interior of the spirals of the secondary coil (in the case of aninterior core) or they will encircle the outer secondary coil,(the outercore.) In both cases the lines of force never touch the secondary helixitself.

In transformers of the first group, as well as the other, the secondarycoil is not traversed by all the lines of force which circulate in theiron. It is only a small portion of the lines of force which detachthemselves, so to speak, from the general magnetic flow which reachesthe secondary coil in closing along short elementary curves. In otherwords, in both cases the secondary coil is influenced not by themagnetic flow in the iron core, but directly by the current in theprimary coil. In arrangements of this kind the iron core, although itaugments the inductive capability of the primary coil, absorbs quit-eunproductively too great a number of lines of force in itself. Such isthe condition of things when the primary circuit is closed and the magnetic flux is produced. The nature of the lines of magnetic force andtheir mode of formation is not at present well determined. According toPoyting and other physicists the energy of magnetic force flows from theexterior, and when the current is on it distributes itself in the ironcore by the lateral surface of the cylinder or ring; but the mode ofgrouping of theselinesatthe moment of their entrance into the iron coreand their distribution on the surface of the core is unknown. From thispoint of View and admitting that the most favorable moment of inductionwill be precisely that at which the force of the magnetic energy flowsfrom the exterior into the iron core by its lateral surface it remains,nevertheless, improbable that in transformers of the two groupsmentioned the lines of force can at the moment of theirintroduction intothe iron traverse in its totality the secondary coil. The greaterquantity will certainly pass outside the secondary coil. Still theamount of induction depends upon the intersection of the coil to beinfluenced (the secondary coil in the transformers) by the lines ofmagnetic force, and the effect of induction becomes greater as thenumber of lines of force which intersect with the coil increases. Itfollows that a real advantage would be obtained by an arrangement of theapparatus such that the magnetic flux which circulates in an iron coreshall pass in its totality across the secondary coil. My arrangement oftransformers, Figures 1 and 2, fulfills this condition. In thisapparatus the secondary helix :EZfl Z, is influenced in the first placeby the current in the primary helix :hZ FZ and in addition by the wholeof the magnetic flux which is developed in the iron core A A by theaction of the primary coil upon this core. In transformers on my system,as in dynamo-electric machines, the loss of magnetism in the air is onlyvery small, and almost the whole of the lines of force which flow in theiron core encounter the secondary coil in their course and traverse itat right angles.

Arrangement ofthc trcmsfoqanew-The core consists of blades or thinplates cut (by means of a stamp) from sheet-iron or soft cast-iron. Theplates A A, the shape of which is shown in Fig. 1, are arranged in theform of a ring and inserted at top and bottom into two insulatingdiubs BB. The primary coil 311 1 1,

IOC

is arranged in the vertical cavity ab Within the interior of the core,Fig. 1, and the secondary coil :Hfi l is arranged outside the firstinform of a flat ring of small height, but of great breadth, in thedirection of the diameter of the ring. The secondary coil of this shapeis placed in a narrow channel ed in the core, extending substantially atright angles to the cavity or slot ab. The ends of the two coils are ledto corresponding terminals on the insulating-hub. By this arrangementthe lines of force meetin their circuit a channel ed, and thischannehalthough containing air, being narrow and long, only slightlyincreases the resistance of the magnetic circuit. This channel, also,which cuts the mass of the core across the direction of the lines ofmagnetic force increases very considerably the rapidity ofdemagnetization and weakens the effect known by the term hysteresis. Inthis Way it lessens the loss of energy expended in internal Work intransformers of other systems. The thin iron plates of the core areinsulated one from another by air. This arrangement of core has thedouble advantage (a) of completely avoiding Foucault currents and (b) ofincreasing the cooling-surface. In short, in its outer shape mytransformer resembles an air-heating stove or a stove with exteriorfins. All

the heat developed by the action of the currents in the primary andsecondary coils is dissipated in the atmosphere radiating from theenormous lateral surface of the plates of the core and by their fins.The primary and secondary coils are able to carry a current of veryconsiderable volume Without producing injurious heating of thetransformer.

I claim as my invention 1. An electrical transformer having a core ofspaced iron plates provided with a vertical slot Within the corecontaining the primary coils, and a slot extending substantially atright angles to the first-named slot and containing the secondary coils,substantially as described.

2. An electrical transformer having a core composed of spaced radiatingplates made up into a ring provided with a vertical slot within the corecontaining the primary coils, and a slot extending substantially atright angles to the first-named slot and containing the secondary coils,substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

